I have a Clearvue 1800 that I’ve been using for about half a year. It’s in my basement and I had to do a few tricks to get it to fit with a smallish overhead area. One of those “tricks” is that my bin is a short plastic storage container about 15”x15”x24”. Although it has a lid and closes up, I’d say it’s not a super tight fit and there’s air leakage. On the other hand, it’s far from just being some open area under the cyclone, either.

Yesterday I was cleaning out the catch under the filters (for the first time) and there were a ton of chips in there. Like, 2-3 bins worth, probably going halfway up inside of the filters themselves. Definitely a lot of heavy junk that I think should have cycloned-out. So I’d say that over the 6 months I’ve been using this, maybe 2/3 of my chips ended up cycloned-out and 1/3 went where they shouldn’t have.

I notice that when in use, the cyclone will swirl chips toward the bottom of the cone, but they don’t tend to fall into the bin. Do you think not having an airtight bin is responsible for this? (I’ve probably answered my own question here.) Furthermore, is there a more detailed explanation (maybe Bill Pentz has one) on the physics of this and why you need a tight bin?

Thanks,

-Chris

8 replies so far

It is absolutely your problem. Any leakage into that bin will allow that air to carry debris right into the filter. That said, you may always find a little of the very finest dust getting past the bin, but nothing like you described.

This is caused by an air leak, and your bin is the most likely culprit. When I first set up my CV I tried putting trash bags inside the bin, with a weight inside to ensure that the bag didn’t get sucked into the cyclone. When I operated this way I get roughly the same results that you are seeing. When I took the bag out I started getting almost nothing in the clean-out below the filter. The only time I end up getting debris in there now is when I overfill the bin, which happens from time to time when I am running the planer.

I think it makes sense then, for my next project to be a custom bin. Given my low clearance, I think I’ll do it as a chest, with a lid that has a gasket.

It would be nice to have some 6” pipe coming out of the lid, with some way to easily couple it to the bottom of the cyclone. I’m not sure if there’s a hardware solution out there that might work well, but any suggestions would be great. The idea would be to have the bin height stay as tall as possible.

Yup, air leak in the bin. This happened to me once when I didn’t tighten down the hose from the cyclone to the bin tight enough and it slipped off a bit.

The real PITA part of it is that you get all the junk into the cleats of the filter. Took forever blowing compressed air into there to knock the chips out. If you’ve got the Wynn Nano filters, it’s likely you’ll have to do the same. According to Dick Wynn, the abrasion from knocking the pleats around from the inside could cause some damage.

To prevent everything from getting into the filter pleats in the future, I got some quilt batting from a craft store and basically created a lining that protects the filters. The batting is very loose, so it really only catches the biggest stuff, but the good thing here is that I think it’s loose enough to not adversely affect the back pressure.

I accidentally screwed up one time since then, but it seems to have worked as designed.

Oh yeah, and as to what the physics are of what’s going on… when there’s an airtight connection between the drum and the cyclone, the pressure in both are roughly the same and gravity is able to pull the heaviest particles down out of the cyclone (the lighter particles will continue swirling around until you turn it off, and the lightest fines will just go through to the filter).

If you have a leak in the bin, there’s a negative pressure environment in the cyclone with respect to the bin itself and gravity isn’t enough to overcome the momentum from air coming in at the bin. You then have air coming in at the hose inlet of the cyclone as well as the bottom. Two completely different vectors and it ruins the cyclone effect. As a result, the majority of the debris will just go out via path of least resistance – that’s through the impeller into the filters.

Thanks everyone. So it’s either capital-A Airtight, or you’re going to have this issue, looks like. Might also be a situation where I’ll want to go at the fliters with some compressed air. It does seem like my airflow isn’t as good as when I first ran it.

I also have a clear view, I wonder if the fact that the bin is very shallow is also part of the problem.I believe that because the bin is shallow, the cyclone tends to suck the debris back up.I also have filled my filters once.MY 2 cents